Researcher examines lingering joint pain from Lyme
For those who suffer from aching joints even after treatment for Lyme disease, it’s long been a mystery why their symptoms don’t improve. But a researcher now has a clue: fragments of the bacteria that cause the disease may linger in joint tendons.
Dr. Linda Bockenstedt, a rheumatologist and professor at Yale University, authored a recent study on the syndrome. She is a colleague of Dr. Peter Krauss and Dr. Marie Diuk-Wasser, both of whom are Yale researchers who study tick-borne illnesses and collect data here on Block Island.
The research by Dr. Bockenstedt and her team is published in the Journal of Clinical Investigation. The study subjects were mice, although the research began with Bockenstedt’s observations of her human patients with Lyme disease. “An enigmatic feature of Lyme disease,” the summary of the report in the journal states, “is the slow resolution of musculoskeletal symptoms that can continue after treatment, with some patients developing an inflammatory arthritis that becomes refractory to antibiotic therapy.”
In that study, Dr. Bockenstedt discovered the remnants of Lyme disease spirochete bacteria in the joints of immunodeficient mice after treatment with antibiotics. The remnant DNA of the bacteria were in the tendons where they insert into bones. These fragments were not present in normal mice, and even in the immunodeficient mice, they disappeared after a couple of months.
It is hard to find a living spirochete after several days of antibiotic treatment, Bockenstedt says. She adds that most people treated with antibiotics find their symptoms resolve rapidly and even for those with lingering fatigue and joint pain, the vast majority are completely better within six months.
About 10 percent, however, develop an antibiotic-refractory Lyme arthritis with a single swollen joint that persists. Removal of the fluid has not shown any bacterial DNA, but Dr. Bockensted theorizes perhaps the tendons retain fragments of the DNA, as the mice tendons did.
Human tendons can be biopsied only when they are removed for joint replacement. So Dr. Bockenstedt will not be continuing this line of research in people yet. She will, however, continue with another line of her research, developing a better diagnostic antibody test to detect the illness.
The current test is based on organisms grown in culture that may not express all the proteins present in the bacteria. Her team has isolated a panel of proteins from mouse skin and is testing them to learn whether they will be useful.
Dr. Bockenstedt has been recruiting people within the first month or so of infection with Lyme to test the new diagnostic test. Thus far, the study is being conducted at only one location, but Bockenstedt says she may try to expand to other locations next year, and Block Island is in her sights.
Meanwhile, those interested in the recent work can read it online in the Journal of Clinical Investigation, Volume 122, Issue 7 (July 2, 2012).